Read Model / Projection Generator

Creates Read Model infrastructure for CQRS read side with optimized query models.

When to Use

Component Characteristics

Read Model

• Optimized for queries
• Denormalized data
• Eventually consistent
• No business logic

Projection

• Builds read models from events
• Handles event streams
• Maintains synchronization
• Idempotent processing

Repository

• Query-focused methods
• Returns read models
• No write operations

Generation Process

Step 1: Generate Domain Read Model

Path:

src/Domain/{BoundedContext}/ReadModel/

1. {Name}ReadModel.php

   — Immutable read model with fromArray/toArray

2. {Name}ReadModelRepositoryInterface.php

   — Query-focused repository interface

Step 2: Generate Application Projection

Path:

src/Application/{BoundedContext}/Projection/

1. {Name}ProjectionInterface.php

   — Projection contract

2. {Name}Projection.php

   — Event handlers building read model

Step 3: Generate Infrastructure

Path:

src/Infrastructure/{BoundedContext}/

1. Projection/{Name}Store.php

   — Store for insert/update/upsert

2. ReadModel/Doctrine{Name}Repository.php

   — Repository implementation

Step 4: Generate Tests

1. {Name}ReadModelTest.php

   — Read model serialization tests

2. {Name}ProjectionTest.php

   — Projection event handling tests

File Placement

src/Domain/{BoundedContext}/ReadModel/

src/Domain/{BoundedContext}/ReadModel/

src/Application/{BoundedContext}/Projection/

src/Application/{BoundedContext}/Projection/

src/Infrastructure/{BoundedContext}/Projection/

src/Infrastructure/{BoundedContext}/ReadModel/

tests/Unit/

Naming Conventions

{Name}ReadModel

OrderSummaryReadModel

{Name}ReadModelRepositoryInterface

OrderSummaryReadModelRepositoryInterface

{Name}ProjectionInterface

OrderSummaryProjectionInterface

{Name}Projection

OrderSummaryProjection

{Name}Store

OrderSummaryStore

{ClassName}Test

OrderSummaryProjectionTest

Quick Template Reference

Read Model

final readonly class {Name}ReadModel
{
    public function __construct(
        public string $id,
        // ... denormalized properties
        public \DateTimeImmutable $createdAt,
        public \DateTimeImmutable $updatedAt
    ) {}

    public static function fromArray(array $data): self;
    public function toArray(): array;
}

Projection

final class {Name}Projection implements {Name}ProjectionInterface
{
    public function project(DomainEventInterface $event): void
    {
        match ($event::class) {
            OrderCreated::class => $this->whenOrderCreated($event),
            OrderShipped::class => $this->whenOrderShipped($event),
            default => null,
        };
    }

    public function reset(): void;
    public function subscribedEvents(): array;
}

Usage Example

// Query read model
$orders = $orderSummaryRepository->findByCustomerId($customerId);

// Project event
$projection->project($orderCreatedEvent);

// Reset projection for rebuild
$projection->reset();

Database Schema

CREATE TABLE order_summaries (
    id VARCHAR(36) PRIMARY KEY,
    order_number VARCHAR(50) NOT NULL UNIQUE,
    customer_id VARCHAR(36) NOT NULL,
    customer_name VARCHAR(255) NOT NULL,
    status VARCHAR(50) NOT NULL,
    total_cents BIGINT NOT NULL,
    created_at TIMESTAMP NOT NULL,
    updated_at TIMESTAMP NOT NULL,

    INDEX idx_customer (customer_id),
    INDEX idx_status (status)
);

Anti-patterns to Avoid

References

For complete PHP templates and examples, see:

• references/templates.md

  — Read model, projection, store templates

• references/examples.md

  — OrderSummary example and tests

• references/event-sourcing-projections.md

  — Event replay projections, versioning, checkpoint tracking, async workers